This was the first thing i started with: check the stomach parasites, re-balance the flora.
I think manipulating the major neurotransmitters like that is a band-aid.
So that people should be careful with SSRI. It looks like they exacerbate AF situation (and also 5-HTP, trytophan).
I have read that about 95% of serotonin produced in the gut so that gut stimulation such as: bloating, scratches, upset stomach, etc. increases productions of serotonin. High levels of serotonin would cause upset stomach, IBS symtpoms.